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		<h2 id=slogan>Generic SCSI Target Subsystem for Linux</h2>
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				<h1>Comparison</h1>
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					<li><a href="comparison.html">Features comparison</a></li>
					<li><a href="scstvslio.html">SCST vs LIO/TCM</a></li>
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					<li><a href="mc_s.html">MC/S vs MPIO</a></li>
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				<h1>SCST vs LIO/TCM</h1>
				<p><a href="http://linux-iscsi.org/" rel="nofollow">LIO</a>,
				from recently being renamed to TCM, is another independent from SCST implementation
				of SCSI target framework for Linux. It's started as PyX iSCSI target and then was
				accommodated to other transports. But it's still in many kinds iSCSI-oriented.
				You can find an example when people are not happy with it
				<a href="http://thread.gmane.org/gmane.linux.scsi/65703/focus=66749">here</a>.</p>

				<p>LIO maintainer, Nicholas Bellinger, is very good in building personal relationships and promoting LIO,
				although often using misleading half, less-then-half and simply deceitful statements
				about LIO current state, capabilities and future directions as well as about its competitor, SCST.
				For instance, he setup LIO targets comparison page with obviously wrong statements about SCST, like
				that it isn't fully zero copy or it isn't a generic target engine (while LIO, of course, is fully
				zero-copy and fully generic target engine). Any
				<a href="http://sourceforge.net/mailarchive/message.php?msg_id=21741080">attempts</a>
				to correct it were simply ignored.</p>

				<p>With those tricks Nicholas Bellinger was capable to attract key Linux kernel developers, and
				they suddenly changed their opinion about Linux SCSI target subsystem in the opposite direction.
				They previously asserted that
				in-kernel SCSI target is the wrong direction, SCSI target must be in the user space, so
				STGT is what everybody needed. Now their opinion is that SCSI target driver should be in the kernel space
				and the only target good for them is LIO, doesn't matter that:</p>

				<ol>
					<li><span>SCST is a lot more mature and advanced</span></li>

					<li><span>SCST from the beginning is a generic SCSI target</span></li>

					<li><span>SCST has a lot more features</span></li>

					<li><span>SCST has better performance</span></li>

					<li><span>SCST has a lot more users</span></li>

					<li><span>SCST has much bigger community</span></li>

				</ol>

				<p>So, rejecting base principles of the Linux kernel community that the best code should win, the worst
				code was chosen.</p>

				<p>You can find more background behind choosing LIO as the mainline kernel SCSI target
				subsystem if you read <a href="http://thread.gmane.org/gmane.linux.kernel/1078109/focus=1078310">this thread</a>
				as well as searching for targets related topics in Linux kernel and Linux SCSI mailing lists.</p>

				<p>Particularly notable is that James Bottomley from the beginning was telling that SCST
				can't be merged in the mainline kernel, because it doesn't offer a drop in replacement for STGT
				to avoid having 2 target infrastructures in the kernel at the same time. But, since LIO can't
				offer user space backend drivers and doesn't have ibmvstgt driver analog, for LIO the drop in replacement wasn't
				a requirement, so 2.6.38+ kernels successfully have both STGT and LIO.</p>
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